groff r



Mgrch23, 1937. J. c. GROFF PERFORMANCE GAUGING MEANS FORHPRIME MOVERSOriginal Filed Ju ly '7, 1950 2 Sheets-Sheet 1 ATTORNEYS March 23,1937., 1c; GROFF' f Re. 20,303

PERFORMANCE GAUGING MEANS FOR PRIME MOVERS Original Filed July '7, 19302 Sheets-Sheet 2 INVENT R Ciao- A. KIA- l 11:1 AM.

ATTORNEYS Reissued Mar. 23, 1937 PATENT:

PERFORMANCE GAUGING MEANS FOR PRIME MOVERS Joseph C. Grofl' Allentown,Pa.

Original No. 1,982,859, dated December 4,1934, Serial No. 466,111, July7, 1930. Application for reissue November 18, 1936, Serial No. 111,402

4 Claims. (cue-51) This invention relates to an improved gauging devicefor determining conditions of, and the power developed by, the expansivemedium .within the power cylinder of a piston type of prime mover.

At the present time it is the common practice to determine the powerperformance or work performance of piston type prime movers by takingso-called indicator cards and afterwards computing the mean effectivepressure from these cards by planlmeter operations, etc. Such anoperation islaborious and time consuming. Experience has demonstratedthat a fairly accurate indication of the engine output conditions can bedetermined from the instantaneous condition existing in the cylinderjust prior to the release of the expansive medium from the cylinder bythe usual exhaust valves or ports.

The present-invention utilizes this fact to enable the relative gaugingto be made of conditions within the power cylinder and obviate the useof the usual indicator card devices which have sides in the provision ofa gauging means to permit the averaging of a number of successiveinstantaneousdeterminations whereby a general average of the performanceof the engine may be secured.

Another object of the present invention resides in the provision-of agauging means for determining the performance of the prime mover of thepower piston type in which pressure determinations may be secured whichmay be coordinated to indicate the work and power developed by theengine by the comparison'with established standards.

A further object of the present invention resides in the provision ofagauging means adapted for use with a prime mover of the power pistontype and in which prime mover a multiplicity of cylinders are provided,the gauging means being I 5 during the running of the engine.

Further and other objects of the present invention will be hereinafterset forth in the accompanying specification and claims and'shown in thedrawings which by way of illustration show. what I. now consider to bepreferred embodiments of the invention.

In the drawings: I

Figure l is a sectional view of a piston type of prime mover of the fourcycle single acting Diesel type of internal combustion engine with myimproved gauging po Fig. 2 indicates a typical indicator card such aswould be taken from a'prime mover of the type shown in Fig. 1, undermaximum load (shown in full lines) and fractional load conditions (shownin dashed lines) Fig. 3 is a view showing my improved gauging means asapplied to a single acting two cycle Diesel type of intern-a1 combustionengine;

Fig. 4 shows the indicator cards which would be taken from a prime moverof the type shown in Fig. 3, under maximum load (shown in full lines)and fractional load conditions (shown in dashed lines) Fig. 5 shows thearrangement of multiple gauging ports upon a two cycle double actingtype of internal combustion engine;

Fig. 6 shows the relation of gauging ports on a four cycle double actingtype of internal combustion engine;

Fig. '7 shows one embodiment of the condition determining device whichmay be used, in which a temperature reading is taken of the conditionsin the engine;

Fig. 8 is another embodiment of the determining device in which pressuredeterminations are made of the operating conditions;

Fig. 9 is a view showing a diflerent embodiment of the determiningdevice in which a manometer type of pressure reading device is employedand in which Venturi means are provided for controlling and averagingthe action upon the manometer; and

Fig. 10 is an illustration of the determining devices as applied to amulti-cyiinder engine and in which means is provided for individuallyobserving the relative operating conditions in the different cylinders.

Referring now to the drawings, in more detail in Fig. 1, 20 is theengine cylinder provided with the usual inlet and exhaust valves andwith a reciprocating power piston 2|. Extending through the side wall ofthe bore of the cylinder 20 is a gauging port generally designated 22and placed in such position with respect to the piston that the sensingport is adapted to be uncovered by the piston substantially at theinstant just prior to the time when the exhaust valve opens and permitsthe release of the expanding medium from the cylinder to the outsideair.

In Fig. 3-the same reference numerals are ap plied to similar parts. Itwill be noted in this figure that the using port 22 is disposed slightlyabove the top of the exhaust ports which are conl0 ventionally providedin two cycle engines. The

exhaust ports in this view are designated 22. Ex- I perience hasdemonstrated that a comparative gauge of the performance of an enginecan be made by an accurate measurement of the pressure existing in thecylinder Just before the instant of releaseof the medium from thecylinder by the exhaust valve or by the exhaust port in a two cycleengine. On the indicator cards shown in Figs. 2 and 4 such exhaustrelease pointis indicated by the line 24. In Figs. 1 and 3 the positionof the gauging port in the cylinder wall with respect to the piston issuch that the gauging port is opened up by the piston Just before thisexhaust release instant. Such point of prior opening of the gau ing portin Figs. 1 and 3 is indicated by reference numeral 2!, reference numeral24 being likewise applied to these figures for comparison with Figs. 2and 4.

Referring now to Fig. 5, in this, embodiment there is a double actingtwo cycle type of piston which will be given the same reference numeral2| operating in cylinder 22, and in order to determine the conditionsexisting in each end of the cylinder, two gauging ports 22 are provided.one

cooperating with one end of the piston and the other with the other end.As in Fig. 3, ports 22 are adapted to be uncovered by the piston justprior to the uncovering by the piston of the exhaust ports 22. Assumingpiston 2| to be moving downwards. the top gauging port 22 is shown asabout to be uncoveredby the upper part of said piston, andslightly inadvance of the uncovering of the upper exhaust ports 22.

In Fig. 6 a double acting type of four cycle enzinc is shown and withthis embodiment two gauging ports 22 are likewise provided one of whichisuncovered by the top end of the piston and the other of which isuncovered by the bottom end of the piston to determine the conditionsexisting in each end of the cylinder.

However. with this type of engine in-view of the fact that when thepiston is approaching one end, for example the lower end, the upper portwill be completely uncovered at an incorrect time;

during which combustion and expansionis taking place in the upper end,and provision must be made for closing off the upper port at this timeand for keeping the lower gauging port 22 open and vice versa. This isaccomplished by the 6 valving mechanism generallydesignated at 26 andoperated in any suitable way from the engine crank shaft. v j

Thus, the upper part of piston cooperates with the lower' gauging port22 to determine the performance of the top end of cylinder 22. and asindicated by the dotted line position of piston 2|. its lower partcooperates with the upper gauging port 22 to determine the performanceof the bottom end of the piston.

I The determining devices will now be explained.

In making determinations, while an engine is operated with the gaugingport and where a gauging port is utilized. it will be appreciated that anumber of successive samples are taken, 7 so to speak. of the expansivemedium within the so,sos

power cylinder upon each uncovering of the gum tions and of averagingreadings is shown in Fig.

'7. Here a chamber generally designated 2I is provided having itsinterior in communication with the gauging port through a valved conduit22. Within the vessel 21 is a pyrometer element 29 of any conventionaltype. Such element is connected to the usual temperature indicatinginstrument 22 which may be of any type.

It will be understood that each time the gauging port is uncovered bythe piston a small quantity of hot "pre-e'xhaust" gas will be admittedinto the interior of the vessel 21 and this intermittent supply of hotgas will serve to maintain a uniform average temperature which will beindicated at 22. v Preferably the vessel 22 is insulated to preventexcessive dissipation of heat therefrom to the atmosphere. Thetemperature reading at an instant Just prior to the exhaust releasepoint 24 (i. e. at point 26, see Figs. 1 and 3, at which point 22 isatan instant just prior to point 24) will give a comparative measure ofthe work developed within the power cylinder and particularly will dothis when this temperature reading is compared with previouslyestablished standards. It will be appreciated that the arrangement ofdetermining device of Fig. '7 will take into account the hotpre-exhaust" gases only and will not be ailected by the uncertaincooling eifects of the scavenging air introduced within the powercylinder during exhaust action in the case of a two cycle type ofengine. with this embodiment of the invention it will be noted that nocheck valve is provided in conduit 22. It

is intended that there be a back and forth flow of the medium throughthe conduit-22. At the preexhaust point 22. the medium would flow fromthe power cylinder of the engine through 22 and into the chamber 21, andthus provide a heating pulse, so to speak, for thermo-couple 29.Following this impulse flow to the right there would be a flow to theleft from the chamber 21 into the power cylinder of the engine viaconduit 22. -It is intended to have a back and forth flow to get a freshpulse ofheated gas to element 29 on each stroke. 1 n

Fig. 8 shows a different embodiment of deter-. mining device wherein thevalved conduit 22 is provided as before leading to the gauging port.This conduit 22 being provided with a ball check 22 which'admits thegases into a pressure averaging chamber 22. A conventional pressuregauge24 is used to show the average pressure conditions in chamber 22 whichwill be understood to closely approximate the average pressureconditions existing in the power cylinder Just prior to the instant ofexhaust.

It will be understood that the pressure gauge' 24 can be calibrated toread directly in terms of work developed in the power cylinder and fromthis reading the power developed can be readily ascertained by anobservation of the speed conditions and with a relative comparison withpreviously established standards. If desired, the pressure gauge 24could be calibrated with a plurality of graduations for different enginespeeds and in this way instant direct power readings can be obtained.

According tothe embodiment .shown in Fig.

,9. the valve conduit 22 leads to a nozzle 25 which discharges into aventuri 24. The venturi .in

- turn intochamber 21 which is preier- '5 venturi. A manometer generallydesignated II is connected to chamber 38. This manometer may belocatedat any desired point even at distances considerably remote fromthe engine. In operation the puffs of gas which are intermit- 10 .tentlydischarged from the venturi create a negative pressure II in chamber Illand this negative pressure is uniformly maintained by providing acomparatively large size volume for chamber 38 and a comparatively smallport opening l9.

5 With this determining device, the average pressure conditions in theengine cylinder just prior to the instant of exhaust action may bedetermined as before. The manometer 40 in effect gives'a relayed readingwhich is proportional to go the 'pre-exhaus pressure in the enginecylinder, the pressure in the engine cylinder effecting the velocitythrough the venturi. With the em- ,bodiment of the invention shown inFig. 9, a gauge of engine performance condition is in- 25 tended to betaken based on the outflow from the cylinder, such outflow being theflow to the right in conduit 2!. An inflow condition exists only on thecompletion of the intake stroke of a four cycle engine. It is desiredthat this intake flow condition be disregarded and this is accomplishedby the arrangement of the venturi 36 and the small port 39 leading intothe averaging chamber 38. It will be understood that the back flowthrough 2! is less than the outflow because the cylinder is very slightat the end of the intake stroke. 0n the other hand, upon outflow thereis a considerable pressure differential between the cylinder and thechamber ll. This considerable pressure diiferential is sufllcient tointroduce a suction effect by venturi l8 and cause a flow of mediumthrough port It. The inflow, however, is so much less in velocity ofpull that there is no considerable appreciable diminution of pressure inI! by the inflow. In other words, the outflow predominates over theinflow condition.

Referring now to Fig. 10, here a multiple cylindered' engine is shownand while four cylinders at are illustrated it is obvious that there canbe any desired number and these cylinders can be of comprise any of thedetermining devices shown in Figs. '1, 8 or 9 and from these determiningde-. vices individual leads ii, .52, 53 and lil'extend to a selectormechanism usually designated 55 56. This reading instrument may be ofany of the types previously mentioned.

- By this construction it will be appreciated that selective comparativereadings-can be taken of the conditions in each cylinder and theseconditions can be compared with the conditions in any other cylinder.Furthermore, the common readinstrument 5. obviates the discrepanciespressure diflerential between 31 and the engineany type. The partsgenerally designated Ill which is adapted to selectively establish thecommunication with a common reading instrument foregoing gauging-devicehas been described in detail in connection with internal combustionengine applications, it will be understood that the gauging meansemployed can also be utilized in steam engines as well whereinreciprocating pistons are utilized.

I claim: I

v 1. A performance gauging means to provide an indication forapportioning the power developed by a multi-cylinder piston type ofprime mover among the individual cylinders wherein an expansive powermedium works against and displaces reciprocating power pistons, saidcylinders being provided with the usual means for releasing andexhausting the expanding medium upon substantial completion of theexpansion stroke, said gauging means comprising in combination, gaugingported passage means located in the sidewall of the bore of eachcylinder andin position at a substantially single point of piston travelto be automatically uncovered by the power piston itself substantiallyjust before the instant of release of the expanding medium from thepower cylinder and means associated with the gaugingiport means fordetermining the pre exhaust pressure conditions existing in each powercylinder Just prior to the release and exhaust of the expansive medium,which condi- -tions are indicative of the power developed by therespective cylinder, whereby the power developed by the engine may beequally apportioned among the individual cylinders through adjustment ofthe'supply of power medium to each cylinder.

2. An apparatus for gauging the power performance of piston type primemovers of the multi-cylinder type and for checking the equality of powerdeveloped by each of the respective cylinders", comprising portedpassage means located atasubstantially single point along the bore inthe sidewall of each cylinder and. in position to be automaticallyuncovered by the piston itself at an instant commencing only during theported passage means of each cylinder for giving an indication ofpre-exhaust pressure conditions which exist in each power cylinder atthe time of uncovering each of the ports by each of the pistonsrespectively, which conditions are indicative of the power developed bythe respec tive cylinder, to thereby show the power peri'ormance of theengine and to show the relative power performance of each cylinderthereof.

3. The invention set forth in claim 2 in which the indicating meanscomprises a pressure indieating device.

JOSEPH C. GEOFF.

